### Please describe the problem.

I'm trying to set up the rclone special remote from [here](https://github.com/Craeckie/git-annex-remote-rclone) (a fork of the recommended that works with newer versions of rclone), for syncing across my laptop and tablet. So far, I've managed to sync everything from my laptop to the remote perfectly well, and I'm now trying to get it to work in Termux.

Having added `git-annex-remote-rclone` to my `$PATH` in Termux, and having installed git-annex itself (which seems to work fine), I tried running `git annex initremote mega type=external externaltype=rclone target=mega-encrypted prefix=git-annex chunk=1MiB encryption=none rclone_layout=lower`, and was greeted (among several linker errors, which are said to be harmless) with the following:

```
Cannot run /data/data/com.termux/files/home/.git-annex/git-annex.linux/bin/git-annex-remote-rclone -- Make sure it's executable and that its dependencies are installed.
```

This is after trying to put the `git-annex-remote-rclone` shell script into a git annex internal binaries folder, though it works nowhere else in my $PATH either. I suspect this is an issue with `proot` not copying in my `$PATH` correctly, though I'm not sure how I would fix this, seeing as I can't find any documentation on how to moify the PRoot flags `git-annex` uses.

### What steps will reproduce the problem?

1. Download `git-annex` into Termux on Android as documented [here](https://git-annex.branchable.com/Android).
2. Download the `git-annex-remote-rclone` folder from [here]() and place it anywhere in your `$PATH`.
3. Run `git init && git annex init` in some directory.
4. Run `git annex initremote test type=external externaltype=rclone target=thisdoesnotexist prefix=git-annex chunk=1MiB encryption=none rclone_layout=lower`. This should print an rclone-related error, but it prints a `git-annex` error as above.

### What version of git-annex are you using? On what operating system?
10.20220121-g0bcb94487 on Android 12 on a Samsung Galaxy Tab S6.

### Please provide any additional information below.

[[!format sh """
# If you can, paste a complete transcript of the problem occurring here.
# If the problem is with the git-annex assistant, paste in .git/anne

# End of transcript or log.
"""]]

### Have you had any luck using git-annex before? (Sometimes we get tired of reading bug reports all day and a lil' positive end note does wonders)

I'm very new to the program, but so far I've found it excellently effective on my laptop! Thanks for a great tool!
